Power clamps are circuits that can be used to protect other circuitry from damage due to overvoltage conditions caused by, for example, electrostatic discharge (ESD) and other noise events. However, power clamps themselves can be damaged if operating voltages and currents become too large. For example, if voltages exceed a certain value, one or more transistors within a power clamp can reach a condition known as secondary breakdown that can cause permanent damage to the clamp. This secondary breakdown mechanism limits the size of the electrostatic discharge (ESD) events that can be safely handled by a power clamp. Techniques and circuits are needed for increasing the robustness of power clamp circuits to ESD.